August Valentine Kautz (January 5, 1828 – September 4, 1895) was a German-American soldier and Union Armycavalry officer during the American Civil War. He was the author of several army manuals on duties and customs eventually adopted by the U.S. military.

On July 16, 1857, Kautz made what is sometimes credited as the first ascent of Mount Rainier. Kautz is reported as having climbed to the edge of Rainier's crater rim, but as he did not make the final walk to Rainier's Columbia Crest, his ascent has often been described as incomplete.[2]

During his time in the Pacific Northwest, Kautz became a supporter of Chief Leschi, who was executed in 1858. Kautz believed the execution was illegal and that Leschi should have been considered a prisoner of war. Shortly before Leschi's execution, Kautz published two issues of a newspaper defending him. The newspaper was called the Truth Teller, and its masthead stated: "Devoted to the Dissemination of Truth and the Suppression of Humbug."

From 1859 to 1860, he traveled in Europe. In August 1860, under Major George A. H. Blake's command, he traveled with recruits on a march from Fort Benton to Fort Vancouver, commanding a detachment of 150 recruits, which broke off from the main group at Coeur d'Alene, Idaho to begin service at Colville Depot, Washington Territory.[3][4] He returned to the Eastern United States in April 1861, shortly after the outbreak of hostilities between the Union and Confederacy.